The present invention relates to implantable medical electrical leads, and more particularly relates to multi-lumen, multi-conductor leads.
In the context of implantable electrical leads, such as those employed in conjunction with implantable pacemakers, implantable nerve stimulators, and implantable cardioverter/defibrillators, it has become clear that leads which are passed between adjacent bony structures within the body have the potential to be damaged due to crushing between these bony structures. A simple mechanism for increasing the resistance of an electrical lead to damage due to crushing is to simply decrease the diameter of the lead body. However, this approach must be balanced with the requirement that the lead body must be large enough to provide room for all conductors and the requirement that the lead remain flexible enough to yield compliantly under crushing forces. One known approach to reduce the diameter is to substitute non-helical conductor for the coiled conductors typically used in implantable leads. For example, having non-helical conductors are disclosed in U.S. Pat. No. 5,324,321 issued to Pohndorf et al and U.S. Pat. No. 4,608,986 issued to Beranek.